With the motor completely disconnected from E-unit, it works flawlessly both forward and reverse. The E-unit rotates the drum flawlessly at each interruption of power. The E-unit fingers are clean, show very little use, and tight against the drum. I rewired (24g flex) the E-unit just to be on the safe side, but mostly to resolder the connections (and, yes, I'm 100% positive the wires are correct; I replaced them one at a time, and even compared it to another engine's E-unit). I also replaced the wire from the collector to the E-Unit (22g flex).
Before I worked on the engine, it would only move forward. I noticed the drum had two small melted spots on the same side so I replaced it but now it doesn't move in either direction; in fact, the motor doesn't make any sound at all. That's why I rewired it but it still doesn't move nor does the motor hum.
The video shows a complete revolution of the drum (8 cycles of plunger) with the voltage meter attached to one brush. The readings were the same for the other brush when I repeated the cycle. When the multimeter was attached to the ungrounded field coil, the readings were zero. Could the issue be w/ the fingers even though they look to be in excellent condition? A bad drum? I'm at my wits end.
